## Search found 63 matches

Wed Jul 01, 2009 9:19 am
Forum: Valveless pulsejet forum
Topic: Few Quick Questions...
Replies: 79
Views: 8825

### Re: Few Quick Questions...

Hi all, I pose the quation about "why does the gas burn at the end of the tube" a while back also [url]http://www.pulse-jets.com/phpbb3/viewtopic.php?f=3&t=5240&p=62323#p62323[url] I just thought I'd have a go at summarising what I have thnuked out since then. A bunsen burn is a device that mixes fu...
Sun Jun 14, 2009 1:52 am
Forum: Valveless pulsejet forum
Topic: Real VPJ stats
Replies: 4
Views: 1200

### Re: Real VPJ stats

Hi Eric, I actually start with a notional full fuel/air charge in uflow, run the simulation for one cycle, and dump its data to calculate the next fuel/air charge volume. This gives me a percentage for the charge for the next cycle. I put that in, runce the sim, export the data and calculate the cor...
Sat Jun 13, 2009 12:20 pm
Forum: Valveless pulsejet forum
Topic: Real VPJ stats
Replies: 4
Views: 1200

### Re: Real VPJ stats

Just to wrap this up, the engines are definitely running at kadency frequencies, not resonance frequencies The simulations show what is probably a 10:1 difference betweent he two. The resonance occurs at much higher frequencies. The timing of the "real" jets seems to be determined by the ratio of co...
Fri May 22, 2009 4:58 am
Forum: Valveless pulsejet forum
Topic: Real VPJ stats
Replies: 4
Views: 1200

### Real VPJ stats

Hi all, I'm not a builder, but dable in the theory. As such, Uflow1d has been invaluable, I am getting to the stage where I think I can ask it meaningful quastions and get vaguely meaningful results. What I would like, is the dimesions of a real pulsejet someone has buld, and its resonant frequency....
Fri May 22, 2009 3:57 am
Forum: Valveless pulsejet forum
Topic: Lockwood simulations, wow
Replies: 22
Views: 4358

### Re: Lockwood simulations, wow

What's the software used?
Tue May 19, 2009 2:16 am
Forum: Valveless pulsejet forum
Topic: Lockwood simulations, wow
Replies: 22
Views: 4358

### Re: Lockwood simulations, wow

Some of the prettiest bowel simulations I've seen.
Mon May 18, 2009 7:00 am
Forum: Valveless pulsejet forum
Topic: Lockwood simulations, wow
Replies: 22
Views: 4358

### Re: Lockwood simulations, wow

Lockwood simuylations

I can't see much pulsing, and the time scale goes up to 10 seconds or so.

"me no unnerstand"

Don
Mon May 18, 2009 6:47 am
Forum: Valveless pulsejet forum
Topic: Engineers do VPJ
Replies: 2
Views: 949

### Re: Engineers do VPJ

Heres another one (one pager)
that sounds like it might be useful, but on my limits of understanding.

I think they are implying that a triangular inlet may be better for a pulsejet than a circular one?

Wed Apr 29, 2009 1:06 pm
Forum: Valveless pulsejet forum
Topic: Engineers do VPJ
Replies: 2
Views: 949

### Engineers do VPJ

http://www.mecheng.adelaide.edu.au/~marjom01/Honours%20projects/2008%20honours%20projects/The%20Design%20and%20build%20of%20a%20pulsejet%20UAV_files/Final%20Report.pdf A bunch of engineers try to build a valveless pulsejet UAD for their Masters. They work on a chinese and a FWE. References to Larry...
Tue Apr 21, 2009 5:36 am
Forum: Valveless pulsejet forum
Topic: Flame Question
Replies: 2
Views: 804

### Re: Flame Question

Here is a conversation i'/ had with someone building forges and the like using LPG burners Hi Tim, I was searching on the internet to find an explanation of the following "why does the flame tend to sit at the end of a burner, rather than moving back up the tube (back-burning)" I found your article ...
Sun Apr 19, 2009 8:55 am
Forum: Valveless pulsejet forum
Topic: What would happen if...
Replies: 9
Views: 1562

### Re: What would happen if...

Sorry, but anything space-going uses hydrogen oxygen mix as a rocket - e.g. Saturn 5, Shuttle, etc.
Sun Apr 19, 2009 1:01 am
Forum: Valveless pulsejet forum
Topic: What would happen if...
Replies: 9
Views: 1562

### Re: What would happen if...

You wouldn't need an air intake then, so the entire engine design would change to become a rocket, rather than a jet.
Sun Apr 19, 2009 12:59 am
Forum: Valveless pulsejet forum
Topic: What would happen if...
Replies: 9
Views: 1562

### Re: What would happen if...

Try injecting some water as well internally. The heat should turn it to steam
improving the volumetric change and cooling the engine a little.

Look up "chemical intercooling" in rev-head space.
They injecta mix of methanol and water.
Sat Apr 18, 2009 2:11 pm
Forum: Valveless pulsejet forum
Topic: What would happen if...
Replies: 9
Views: 1562

### Re: What would happen if...

You could try using Nitrous Oxide in stead of straight O2